Amidst growing fear-based propaganda warning of the threat of Zika virus comes a quiet admission from health officials in Brazil: Zika alone may not be responsible for the rise in birth defects that plagued parts of the country.

While there is some evidence suggesting Zika virus may be linked to the birth defect microcephaly, and the virus has been spreading throughout Brazil, rates of the condition have only risen to very high rates in the northeast section of Brazil.

Since the virus has spread throughout Brazil, but extremely high rates of microcephaly have not, officials are now being forced to admit that something else is likely at play.

Dr. Fatima Marinho, director of information and health analysis at Brazil’s ministry of health, told the journal Nature, “We suspect that something more than Zika virus is causing the high intensity and severity of cases.”